Hearth protection/thickness?

Doing some research on Hitzer coal stove. Manual says it requires 3/8" fiberglass millboard or equivilant or a rating of K-0-84 . Anyone have any idea what a "K" rating of K-0-84 translates to? I know what a K value is but have no idea how to figure out the # they list needed. I was thinking of using 4" solid cinder block with a 1" piece of slate on top. Anyone know if that would suffice?

Maybe they mean between 0 and .84 ?
all I know is the lower the K value the better
... I would think you would be fine with that much masonry

t
hats plenty,just make sure that it extends out front far enough to catch the hot coals that fall off the end of your pan when u remove ashes,i would think a foot would be enough...fill out ur profile tell us where ur from so fred,freetown can steal ya lol...

If i can suggest you can never have enough length in front of the stove. I believe that pea coal no matter how irregularly shaped it is, picks up speed when it hits the bricks that i have in front. I have a short length of 1" square wood that I place at the edge of the bricks anytime I have the front door open. it has saved my hearth carpet and hardwood floor from disaster at least a dozen times in 5 years.

My manual says a 18 ga piece of sheet metal is enough..... I used 1/4" tile on top 1/2" hardee backer board nailed to 3/4" plywood 4'X5'.

Thanks for the info. Emailed Hitzer and they confirmed that what I want to do is more than enough. Said that "any UL listed stove board" would be sufficient. Most likely going to finish out this season with a piece of junk pellet stove we inherited. Ive burnt coal in the past. A hand fed Franco Belge many years ago, what a monster! and more recently a Reading Stoker. Looking to go back to a hand fed. No electricity to use. No electrical parts to break and best of all, no noise in the living area. Biggest problem is finding coal in this area. Upper valley/Grafton NH. Can get bagged for 6.99 a bag, but hoping to find some, preferably loose/bulk, at a cheaper price. We currently have the house on the market, and if/when we sell it we might be moving to Pittsfield MA area. Coal should be more available in that area I would think.

3/8" fiberglass millboard or asbestos millboard is equivalent to 2" of concrete. At least that's what I was told by the inspector that came and looked at my hearth when I installed my wood burning stove.

Those figures are meant mainly for folks who are not planning on a masonry hearth area, generally most masonary jobs are 3+ inches thick (which is more then fine). The suggestion about extending the front area (maybe in a nice semi circle or whatever) is a great idea, otherwise you will surley want a fire rated pad in front after you discover ashes falling off the front edge of the hearth.